Cord tightening device



FIG. 1 is a front perspective view showing my new design for a cord tightening device,

FIG. 2 is a rear view thereof;

FIG. 3 is a front perspective view showing a movable member in a projected position;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view of the embodiment shown in FIGS. 1 and 2;

FIG. 6 is a left side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof. 

The ornamental design for a cord tightening device, as shown and described. 